Middle ear myoclonus: Systematic review of results and complications for various treatment approaches

Tensor Tympani and Stapedial Tendon Reconstruction for Postoperative Hyperacusis after Tendon Lysis for Middle Ear Myoclonus

OBJECTIVE

To present a method for repair of the stapedial and tensor tympani tendons in a patient with hyperacusis after a tendon lysis procedure.

PATIENTS

A 71-year-old professional musician who presented to clinic with debilitating hyperacusis following a tensor tympani and stapedial tendon lysis procedure to treat middle ear myoclonus.

INTERVENTIONS

A novel procedure for reapproximation of the tensor tympani and stapedial tendons into their native insertion points using periosteal grafts and nitinol wire.

MAIN OUTCOMES MEASURES

Stapedial reflex measurements, uncomfortable loudness level, and subjective patient experience.

RESULTS

Postoperatively, the patient had objective improvement in hyperacusis with return of acoustic reflexes in the affected ear and durable improvements in their frequency-specific uncomfortable loudness levels.

CONCLUSIONS

This case describes the debilitating complication of hyperacusis following tendon lysis and highlights the importance of maximizing behavioral and medical measures prior to undergoing surgical intervention for middle ear myoclonus.

Intratympanic Botulinum Toxin Injection as a New Therapeutic Modality for Middle Ear Myoclonic Tinnitus

OBJECTIVE

Middle ear myoclonic tinnitus (MEMT) is a disease caused by myoclonus or abnormal contractive movement of middle ear muscles (MEMs). This translational study was conducted to propose intratympanic botulinum toxin (IT-BTX) injection as a new therapeutic modality to treat MEMT.

STUDY DESIGN

Animal experiment and nonrandomized controlled clinical trial.

SETTING

Laboratory and medical center of an academic tertiary medical institution.

METHODS

For the animal study, male Sprague-Dawley rats were divided into 4 subgroups according to the sacrificing day after IT-BTX injection. After initial hearing tests, randomly assigned experimental ears were intratympanically injected with 1 unit/100 μL of BTX-A, whereas control ears were injected with normal saline. Changes in the hearing thresholds, morphometry of the cochleae, electron microscopy study, and immunofluorescence analysis of MEMs were evaluated. For the human study, 10 intractable MEMT patients were enrolled. The hearing thresholds and the degree of tinnitus distress were observed for changes after IT-BTX injection. All patients were followed up for 3 months.

RESULTS

As for the animal study, there were no significant changes in hearing thresholds and cochlear morphologies in all 4 subgroups of the rats. Significant MEM degenerations and immuno-detection of cleaved synaptosome-associated protein of 25 kDa (cSNAP-25) indicated the efficacy of IT-BTX. MEMT patients enrolled for the pilot clinical trial showed statistically significant improvement in tinnitus after IT-BTX injection. No major complications were noted.

CONCLUSION

The new therapeutic modality of IT-BTX injection for the treatment of MEMT seems highly promising with an excellent result.

COVID-19-Associated Middle Ear Myoclonus in a 10-Year-Old Male

Middle ear myoclonus is a rare condition attributed to abnormal, repetitive contractions of the middle ear muscles including the tensor tympani and/or stapedius muscles. This condition generates objective tinnitus that is characterized by a “clicking” noise that is audible to both the patient and an outside observer. No specific pathophysiologic process has been identified as the cause of middle ear myoclonus, making its diagnosis and treatment challenging. In this report, we present a presumptive case of COVID-19-associated middle ear myoclonus in a 10-year-old male.